None of the mods shown in the work bench touch persistence or the charges themselves.
It looks like the explosive charges used by US and USSR are missing persistence, and thus when a singleplayer/multiplayer mission is loaded, any demo charges don't load with said save.
Neither listed in the persistence config or have a component, so I'm not sure if this is intended or not.
Also happens in current version of experimental (1.8.0.5)